Lamp.



H. SALSBURY.

LAMP.

APPLICATION FILED DB0. 16, 1907.

942,589. Patented Dec. 7, 1909.

WWA/5.9659

HENRY sALsnURY, or LONDON, ENGLAND.

LAMP.

.application inea December 1e, 1907.

To all whom it may concern:

Be it known that I, HENRY SALSBURY, a subject of the King of GreatBrita-in and lreland, and residingat 124k Long Acre, London, Ilngland,have invented `certain new and useful Improvements in and Relating toLamps. of which the following is a specification.

My invention relates pecially applicable to such as are used inconjunction with motor vehicles.

As the beam of light projected from the lamps of a motor or othervehicle is generally of a more or less divergent character,

" any one approaching the vehicle from an opposite vdirection to that inwhich it is traveling, will enter the zone of light at a distance fromthe vehicle `depending on the character of the projected beam. When Atheintervening distance between the vehicle and the observer is short orthe light is of great intensity, as for example when acetylene is usedas the `illuminating agent, it is found that the eyes of the observerare so a'ected that he is unable to locate the exact position of thevehicle. This peculiar effect on the eyesight is termed glaring, and isvery objectionable and dangerous when the vehicle concerned is travelingat a high speed anld is met. by an observer in another vehicle travelingin the opposite direction.

According to the. present invention, by providing suitable surfaceswithin the lens or glass of the lamp, the rays of light which wouldotherwise be projected upward and produce glaring in the eyes of any oneap preaching, are reflected downward and the main beam of light emittedfrom the lamp restricted to a level below that of the line ofvision ofthe observer.

My invention therefore has for its object to provide an improved lens orglass, which will prevent the objectionable effects of glaringespecially noticeable in connection with acetylene lamps.

,My invention consists in a lens or glass of the solid or built up type,in which surfaces are formed for substantially preventing upwardprojection of the rays from the lamp within the limit in which theintensity of the light would be such as to produce glarlng.

My invention further consists in the improved lenses or glasses and lampto be hereinafter described.

' :."erring now the accompanying draw- Spec'cation of Letters Patent.

. characters to lamps, and is es` Patented Bec.. "i, 190%?.

Serial No. 406,822.

ings which illustrate my invention and form part of my specification,and in which like ofreference indicate corresponding parts in bothviews, Figure l `shows a part sectional elevation of a lens constructedaccording to my invention, Fig. 2 showsv asectional elevation of a lampillustrating the action of my 4improved lens or glass.

In carrying my invention into effect according to one form, l provide alens or glass which is formed bycementing or otherwise assemblingtogether in a mount a (Figs. l and 2), a number of horizontally disposedstrips or laininae, Z), of glass or other translucent material. rl`hedimensions of the strips may of course, vary according to circumstances,in the example illustrated the dimensions being leg wide x if thick,rlhe strips or laminae are polished on their upper faces h and ground ontheir lower faces z', so that any rays vof light which strike obliquelyagainst the upper faces of the laminas are to a great extent reflecteddownward, while those which strike against the lower faces are absorbedto a reat extent. The lens is then ground to any esired shape andmounted in a lamp, Fig. 2.

The burner, 0, is placed for example in the focus of a parabolicreflector,l d, which pro'ects the reflected light in a series of parallerays, c, through the laminae, b, of the lens. rlhe direct light from theburner however is projected in a diver` ent beam, the upwardly inclinedrays, f, of which are reflected downward by the upper surfaces of thelaminee, while the downwardly inclined rays, g, are absorbed by thelower surfaces.

rlhe design of the lamp should be such, that any rays which may happento be projected in an upward direction intercept the vision at a pointwhere their ,intensi-ty is so much diminished as to produce noobjectionable results. It will thus be seen that'practically onlyhorizontal and downwardly inclined rays of light are emitted fromthe'lamp.

In some cases the upper surfaces of the laminae may be silvered whilethe lower surfaces ma be ground or coated with a light absorbingmaterial, or may be ground and coated with a light absorbing material,while in other cases both the surfaces of the laminas may be ground.

By means of my invention it will be evident that the rays of light which-would otherwise issuein an upward direction, are

observers line of reflected downwardly or substantially horizontally bythe upper surfaces of the laminas, the downwardly directed rays beingwhlly or partially-absorbed by the non-reflecting or y light absorbingsurfaces on the lowery faces of`the'laminae. The objectionable ef` fectof glaring is thus entirely avoided, as any rays of light which maydisperse in an upward direction are restricted to the zone in whichtheir intensity is sufliciently diminished to produce no objectionableresults.

Having now described my invention, what I'clairn as new and desire tosecure by Letters Patent is I l. As an article of manufacture, a glassvformed of laminas having reflecting surfaces on one side `of saidlaminae and light absorbing surfaces on the other side of same.

2. As anl article of manufacture, a glass formed of laminae having apolished surface on one side of said laminas and a ground surface on theother side of same.

3. In combination, a source of light, a. plurality of translucentlaminas disposed edgewise to the rays of light from said source, meansdisposed between the laminas for reflecting certainof the rays of lightpassing through said laminae, and means disposed between said laminasfor absorbing certain other of said rays of light.-

4C. As an article of manufacture a glass having reflecting and lightabsorbing surfaces disposed edgewise to the light trans-l mittingsurfaces of said glass. I

5. In combination a source of light, and a plurality of translucentlaminas disposed 4 transversely tothe rays from said source, saidlaminas having reflecting surfaces on theiry upper sides yand lightabsorbing surfaces on their lower sides.

6. As an article of manufacture a glass having a plurality of parallellight absorbing surfaces disposed edgewise to the light transmitting.surfaces of said glass.

7. As a vnew article of manufacture, a glass having a plurality oflight-absorbing surfaces disposed edgewise to the light transmittingsurfaces of said glass.

In testimony whereof I have signed my nameto this specification in thepresence of two subscribing witnesses` L HENRY SALSBURY.

lVitnesses:

ALBERT E. PARKER, FRANCIS J. BIGNELL.

